Vertical pull broaching machine



y 19, 1931- F; J. LAPOINTE 1,806,106

VERTICAL PULL BROACHING MACHINE Filed Jan. 4. 1 29 2 Sheets-Sheet 1 5%, HIS

May 19, 1931. F. J. LAPOINTE 1,306,106

' VERTICAL PULL BROACHING MACHINE Filed Jan. 4, 1929 2 Sheets-Sheet 2 Patented May 19, 1931 uurrsn s'ra'ras PATENT OFFICE FRANCIS J. LA PO INTE, OF ANN ARBOR, MICHIGAN VERTICAL PULL BROACHING NIACHINE Application filed January 1929. Serial No. 330,345.

My invention'has for its object to provide a means whereby a pull broach may be readily inserted in the work and connected to the draw bar or head of a broaching machine. The invention enables a rapid broaching of articles in that it provides a means whereby the broach may be readily disconnected from the head upon its return, the

lwork inserted in place and the shank, or starting end, of the broach inserted in the parts of the broaching machine that particularly relate to the construction-containing the invention, are shown in the accompanying drawings,

ig. 1 is a side view of the head of a broaching machine. Fig 2 is an end view of the part illustrated in Fig. 1. Fig. 3 is a view of a section taken on the plane of the line 3-3 indicated in Fig. 1. Fig 4 is a view of a section taken on the plane of the line 44 indicated inFig. 3. Fig. 5 is a view of a section similar to that shown in Fig. 4.v It illustrates parts located in positions different from that shown in Fig. 4;. vFig. 6 is a view of a' section taken on the plane of the line 66 indicatedin Fig. 3. Fig. 7 illustrates a top viewjof a part of the locking member. v

In the particular form of construction illustrated in the drawings, the broach draw head 1 is connected to the draw plate 2 of a vertical pull broaching machine. The draw plate 2 may be located on vertically disposed guide bars 3 and operated by a hydraulic means to reciprocably move the draw plate 2 along the guide bars 3. A work plate 4 may be secured to the guide bars 3 by suitable locking rings 5. The draw head 1 may be secured to the draw plate by means of a suitable threadedstud l0 and a nut 11.

"12 so as .to locate the The draw head is provided with means for automatically engaging the pull broach upon mere insertion of the pull broach into the head.

The work is located below the work plate 4 and the broach is inserted through the work and throughthe work plate or bed 4 and pushed up into the head wherein it is engaged. Upon the completion of the vertical movement of the broach'on the. work, the work drops from the work plate, or is removed, and the draw head descends. The

broach is disconnected from the head which permits the broach to drop from the head 4, whereupon the succeeding article is located in position and the shank ofthe broach is inserted through the work andinto the head. i I The head is provided with a block 12 that is integrally connected with the threaded stud 10. The block 12 is slotted as at 13 and a pair of side blocks 14, having projecting parts 15, are bolted to the sides of the block protruding parts 15 within the slot 13 of the block 12. The pro truding parts 15 are provided with surfaces 16 that are inclined to the axis of the stud 10 so. as toslope away from the stud and towards its axis. A pair of dogs 17 are "also located within the slot 13 and are provided with surfaces 18 that conform to the surfaces 16' of the side blocks 14. The dogs 17 are so formed as to have a sliding movement on the surfaces 16 and thus to approachor recede from each other according to the direction of movement of the dogs 17 relative to the side blocks 14:. r V In order to engage. the shank end of the broach. the dogs are provided with suitable engaging surfaces and the broach is provided with corresponding engaging surfaces that coact therewith to be locked by the engaging surfaces of the dogs. Any suitable recesses and progect ons that are complementary 1n their relatlon may be formed on the dogs and the shank of the broach for establishing connection between the broach and the dogs. In the particular form of construction shown, the shank end of the broach is threaded as at 20, while the dogs 17 are also threaded as portions 21 of the;dogstlrat form extended lateral surfaces of the dogs for guiding the dogs in their movements within the slot 13 of the block 12. Thus, in order to connect the broach to the head, the breach is merely inserted through the lower end of the slot 13 and between the protruding parts 15 The dogs 17 are slid along the surfaces 16 until the teeth or thread of the 'dc gsmesh with the teeth or thread of the breach. Preferably, a plate "24 is bolted to the lower side of the block 12 and is provided with an opening 25 which forms a guide for the shank of the breach and also provides a means that cooperates to hold the breach "in pos1t1on.

In order 'to release the dogs 17 from the breach, a release bar is located in a slot QQeXtending transversely through the block 12. "The release bar is provided with an opemng 31 through which the end of the broach may freely pass when it Is inserted into the head or withdrawn therefrom. The

bar is alsoprovided with laterally extending portlons 32 that are adaptedtoengage the v lowerends of the dogs 17. "When, therefore,

the release bar israised, the dogs will belifted and will be loosened from the breach.

The dogs may be separated by reason of in:

clin'edsurfaces formed by the engaging teeth orthread of the breach and the correspond ing inclined surfaces formed on the dogs. In the particular form of construction shown, the lower ends ofthe dogs 17 are providedwith "the surfaces 33 that are inclined outwardly and-downwardly to the longitudinal axis of the head. Therelease bar 30 "also provided with in lined surfaces 34- that correspond to the inclined surfaces 33 of m the dogs so that wnen 'the release bar 30 1S raised, the dogs 1'? W111 tendto'separate by 'sliding laterally over the surfaces Thus, the dogs and the breach may be provided with plane engaging interlocking surfaces rather than 1ncl1ned engaging surfaces and "by reason of the inclined surfaces 33 and 3% the dogs will disengage the broach.

The release bar 30 may he raised by any suitable means. In the particular form of construction shown, a lever 40 is pivotally supporte'd by means of, and is keyed to one the side blocks 1a. An arm 42is connected to the opposite end of the pin 41 and the lever 40 and the arm 4-2 are'provided with oblong openings 4A in which the ends of the release bar 30 are located whereby, notwithstanding the arcuate movements of the lever and the arm about the axis of the pin 41, the release bar will move rectilinear-1y in the slot 31. When, therefore, it is desired to release the broach from the head, the lever 40 is raised which raises the release bar 30 and the dogs 17 separate. This will drop the broach from the head.

If desired, an automatic means may be provided for releasing the broach from the head :upon the completion of the downward movement of the head. This may be performed bym'eans of a dog that is pivotally supported at. any desiredpoint for freerangular movement in one direction and for limited movements in the opposite direction,

namely, in the return direction of the movement o'fthe head when it is desired to release the 'broach. The dog 50 may be ,pivotally supported onth'e'bracket 51 that is connected to the work plate 4; When, therefore, the draw head 1 is raised, the lever 40 will rotate andvpass the dog 50. The dog 50 is. so formed;

as to provide a stop 52 tolimitits return movement so that wh n the draw head 1 returns the end ofthe lever 40 will engage the dog 50 and before the'comple'tion of the downward stroke of the draw head, the leverwill rotate suthciently to operate the release bar 30 to'release the .broach from the draw head. I I

' In order to maintain the dog 17 in cooperative relation within the block-12, the dogs. 17 may be interconnected by means of abar- 55 located'in a slot formed in a side of each of the dogs. The bar 55 is, preferably, connected to one of the dogs 17 r and is -slidably located in the slot formedvin theother dog'e 17. r This operates to inaintai'n the dogs in substantially the "same, relation with respect to the inclined surfaces 16 to move together.

Iclaim: p o a 1. In a draw head for vertically operated pullibroaching machines, the draw head havinga pair of, inclined surfaces extending towards the axis of the draw head and downwardly, a pair? of dogs 'slidably supported on the said 'surfacesandhaving inwardly extending engaging parts for engaging 'jthe broach, the inwardly extending engaging parts having surfaces inclined upwardly to and outwardly from 'the 'axis of thedraw and causes them head, a release bar extending, beneath the lower ends of the dogs for engaging the dogs, and means for raising the releasebar, the last named surfaces operating to separate the dogs and release the broach when therelease I I I bar is operated. end of, a pm 41 that extends through 'one of pull "broachin machines, the :draw head having a pair of inclined surfaces extending towards the axis of the draw head'and downwardly, a pair of dogs slidably supported on the said surfaces and having inwardly extending engaging parts for engaging the broach, the lower ends of the dogs having surfaces that are inclined to the axis of the draw head and extending downwardly and outwardly, a release bar for engaging the said surfaces to separate the dogs and release {)he broach, and means for raising the release 3. In a draw head for vertically operated pull broaching machines, the draw head having a pair of inclined surfaces extending towards the axis of the draw head and downwardly, a pair of dogs slidably supported on the said surfaces and having inwardly extending engaging parts for engaging the broach, the lower ends of the dogs having surfaces that are inclined to the axis of the draw head and extending downwardly and outwardly, a release bar for engaging the said surfaces, the release bar having inclined surfaces that correspond to the inclined end surfaces of the dogs, and means for raising the release bar;

4:. In a draw head for vertically operated pull breaching machines, the draw head having a pair of inclined surfaces extending towards the axis of the draw head and downwardly, a pair of dogs slidably supported on the said surfaces and having inwardly extending engaging parts for engaging the broach, the lower ends of the dogs having surfaces that are inclined to the axis of the draw head and extending downwardly and outwardly, a release bar for engaging the said surfaces, the release bar having inclined surfaces that correspond to the inclined end surfaces of the dogs. and a lever pivotally supported on the draw head for raising the release bar.

5. In a draw head for vertically operated pull broaching machines, the draw head having a pair of inclined surfaces extending to wards the axis of the draw head and downwardly, a pair of dogs slidably supported on the said surfaces and having inwardly extending engaging parts for engaging the broach, the lower ends of the dogs having surfaces that are inclined to the axis of the draw head and extending downwardly and outwardly, a release bar for engaging the said surfaces, the release bar having inclined surfaces that correspond to the inclined end surfaces of the dogs, a lever pivotally supported on the draw head for raising the re-- lease bar, a pivoted latch member connected I to a fixed part of the broaching machine and adapted to engage the lever at a point near the completion of the stroke of the draw head to release the broach fromthe dogs.

In witness whereof I have hereunto signed my name to this specification.

FRANCIS J. LAPOINTE. 

